ITMI20100881A1 - TEXTILE STRUCTURE RESISTANT TO IMPACT OF BULLETS AND TO PENETRATION OF CUTTING AND / OR POINTED ELEMENTS AND RELATIVE PRODUCTION METHOD - Google Patents

Description

Textile structure resistant to the impact of bullets and the penetration of sharp and / or pointed elements and related production method.

-

The present invention refers to a textile structure resistant to the impact of bullets and the penetration of sharp elements, such as blades, and / or pointed elements, such as needles or ice picks, and relative production method.

Structures of this type are mainly used to create personal protections, such as articles of clothing (anti-cut and bulletproof vests).

Two types of textile structures are known in this specific sector: structures resistant to the impact of bullets and structures resistant to the penetration of sharp and / or pointed elements.

The known type textile structures which offer the best characteristics of resistance to the impact of bullets include, in general, a structure with â € œunidirectionalâ € or â € œsemi-unidirectionalâ € threads.

Examples of such structures are given by US7.148.162 B2 and EP0683374 B1, both in the name of Andrew D. Park, US5.354.605, EP0191306B1 and US4.623.574 in the name of Allied Signal Inc., WO97 / 00766 in the name of DSM N.V. and EP1.595.105 in the name of Citterio. Such structures have long since replaced the traditional warp and weft fabrics.

The yarns with which these structures are made, so-called ballistic yarns, are constituted by high tenacity fibers as described for example in US 5.354.605 (columns 2-7), which are at least partially impregnated, covered or incorporated in polymeric substances of elastomeric, plastomeric, viscous or viscoelastic type having, in general, an elastic tensile modulus advantageously lower than 41 MPa.

In fact, it is known that the impact resistance of bullets is inversely proportional to the elastic modulus of the polymeric substance that impregnates, covers or incorporates the fibers of the ballistic threads. The fibers that make up the ballistic threads, in fact, in order to absorb and dissipate the energy related to the impact of a bullet, must be able to deform and stretch as much as possible at the same time. This happens precisely through the polymeric substance that connects the fibers together.

The low tensile modulus of the polymeric substance used for these structures allows the fibers to stretch and deform elastically, thus absorbing the incident energy.

These textile structures, while offering good resistance to impact with bullets, do not however offer satisfactory resistance to the penetration of sharp and / or pointed elements.

Currently known textile structures resistant to the penetration of sharp and / or pointed elements consist, in general, of warp and weft fabrics with a "canvas" weave, for example. To these fabrics are applied, with known methods, rigid polymeric substances with an elastic modulus generally higher than 2000 MPa.

Such polymeric substances are, in general, of the thermosetting type, such as for example acrylic, epoxy, phenolic and polyester resins, as described, for example, in US4.522.871.

These textile structures, while offering good resistance to the penetration of sharp and / or pointed elements, do not however offer adequate resistance to the impact of bullets. The polymeric substance applied to them, in fact, rigidly coexists the fibers of the threads, making the structure practically monolithic. A sharp element will therefore not be able to separate the fibers and penetrate through this structure. However, the rigidity of the applied polymeric substance prevents the fibers of the threads from deforming and elongating so as to be able to absorb and dissipate the energy transmitted to them following the impact of a bullet, which, therefore, easily penetrates through these textile structures. .

Furthermore, the rigid polymeric substances of the thermosetting type used to make these structures require polymerization times of a few minutes. For this reason the textile structures, to which these polymeric substances are applied, are pressed discontinuously into sheets of standard dimensions of about 150x250 cm, the subsequent processing of which for the realization of the shapes of a ballistically protective article generates inevitable waste of material.

A further disadvantage related to the impregnation of these textile structures with rigid polymeric substances of the thermosetting type, consists in the fact that these structures, after being impregnated with the resin and before the latter is polymerized, must be stored in special rooms. at temperatures even below 0 ° C to avoid their premature hardening which would not allow the necessary finishing operations to be carried out.

Various thermosetting resins, among which in particular phenolic and polyester resins have an unpleasant odor which remains in the textile structures impregnated with them.

In order to combine both properties of resistance to the impact of bullets and to the penetration of sharp and / or pointed elements, as required by the various reference standards, currently â € œhybridâ € structures are being made including at least two structures, of which the One with properties of resistance to the impact of bullets and the other with properties of resistance to the penetration of sharp and / or pointed elements.

Such hybrid structures, however, are heavy and stiff so garments made from them are uncomfortable for the wearer.

To obviate some of the aforementioned drawbacks, document WO97 / 21334 in the name of Du Pont proposes the use of a thermoplastic resin in the form of a film with an elastic tensile modulus of about 1000 MPa.

However, also in this case there are two solutions: a specific one for the impact resistance of bullets, in which a polymeric film is applied on one of the opposite faces of the structure, and one that is resistant to the penetration of sharp elements and / or pointed, in which the polymer film is applied to both opposite faces of the structure.

Furthermore, these structures offer resistance to the impact of bullets or to the penetration of sharp / pointed elements only at room temperature, while at temperatures above ambient temperature they lose their resistance characteristics.

Finally, from EP1.102.958B1 in the name of Teijin Twaron GmbH it is known the use of a thermoplastic film of polycarbonate (PC), type LEXAN <®> 103 from GE Plastic with a modulus of the order of 2500 MPa. In this case, however, the high viscosity of the polycarbonate film, even if subjected to high pressures and temperatures as described in this document, does not allow to impregnate a sufficient fraction of fibers that make up the threads of the fabric. The fibers, therefore, remain non-bonded together, offering poor resistance to the penetration of sharp and / or pointed elements.

The purpose of the present invention is to propose a textile structure which offers resistance to the impact of projectiles and at the same time to the penetration of sharp and / or pointed elements.

A further object of the present invention is to provide a textile structure which is more flexible than the current ones and which can also be used to manufacture comfortable personal protection articles.

Yet another object of the present invention is to provide a textile structure which is practically odorless and which maintains its characteristics and properties over a wide temperature range.

Another object of the present invention is to provide a method of manufacturing a textile structure resistant to the impact of bullets and the penetration of sharp and / or pointed elements, which is simple to implement and low cost.

These objects according to the present invention are achieved with a textile structure resistant to the impact of bullets and the penetration of sharp and / or pointed elements as set forth in claim 1.

Further characteristics are provided in the dependent claims 2Ã · 12.

These objects are also achieved with a method of producing a textile structure resistant to the impact of bullets and the penetration of sharp and / or pointed elements as set forth in claim 13.

Further characteristics are provided in dependent claims 14-21.

The characteristics of the present invention will become more evident from the following, exemplary and non-limiting description, referring to the attached schematic drawings in which:

Figure 1 is a diagram of a warp and weft textile structure, usable for the production of the textile structure according to the present invention;

figure 2 is a diagram of an interlaced warp and weft textile structure with two layers of overlapping unidirectional yarns, usable for the production of a textile structure according to the present invention;

Figures 3 and 4 show in schematic section the textile structure of Figure 1 before and after pressing.

Figure 1 schematically shows a warp and weft textile structure consisting of a fabric 1 with weft threads 2 and warp threads 3 woven with a plain weave.

In figure 2, instead, a weft and warp structure 11 is schematized with weft threads 12 and warp threads 13 interlaced with unidirectional threads 14 and 15 arranged in two overlapping layers and oriented at 90 ° with respect to each other to form a structure 10.

Both the fabric 1 and the structure 10 act as a basis for the realization of a textile structure according to the present invention.

In the fabric 1 at least part of the weft threads 2 and / or of the warp threads 3 and, in particular, all the weft threads 2 and the warp threads 3 consist of ballistic threads.

In the structure 10 at least part of the unidirectional yarns 14 and 15, of one or both layers, are ballistic yarns, while not excluding that also the weft yarns 12 and the warp yarns 13 comprise at least in part ballistic yarns.

By ballistic threads we mean, as known in the sector, threads made with high tenacity fibers and tensile modulus of elasticity, having the following minimum characteristics:

- Tensile strength> 7 g / dtex (according to ISO 627-1-2)

- Tensile modulus of elasticity> 200 g / dtex (according to ISO R527)

- Energy at break> 8 J / g (according to ASTMD 2256 standard)

Such ballistic yarns, by way of example and not limited to, include aramid fibers, copoliaramides, polyvinyl alcohol fibers, polybenzooxazole (PBO), polybenzothiazole (PBT), high molecular weight polyethylene, glass, basalt or carbon fibers, also in admixture between They.

In a preferred embodiment, the ballistic threads are composed of continuous filament fibers, parallel to each other; however, it is also possible to use twisted, twisted, textured and taslanized yarns, even in mixed ones.

The ballistic threads can be pretreated by impregnation with substances, in particular polymeric substances, known in the sector and consisting, for example, of silicone or fluorocarbon polymers, capable of making the textile structure repellent to water, or other polymers, such as for example polybutenes, polyacrylates, poly-iso-butylene and polyesters, capable of modifying the adhesion characteristics of the polycarbonate-based resin underlying the present invention to the fibers of the yarns.

Finally, the ballistic threads have a titer between 25 dtex and 10000 dtex, preferably between 250 dtex and 3000 dtex.

By varying the count of the ballistic threads used and the number of threads per centimeter present in the structures indicated above, the latter can have a weight varying between 50 g / m <2> and 1000g / m <2>, in particular between 100g / m <2> and 500g / m <2>.

The peculiar characteristic of the present invention lies in the solvent impregnation treatment with a solution of a polycarbonate-based resin, in the form of a mixture or copolymer, of a textile structure made at least in part with ballistic threads.

The impregnation can also be only partial; that is, it can affect even only part of the fibers present in the textile structure, for example even only 10% of them, so that the quantity of fibers of the textile structure that are impregnated with the polycarbonate-based resin varies between 10% and 100% of the total fibers.

Said polycarbonate-based resin dissolved in solvent can be applied, for example, only to one of the two opposite faces of the textile structure with systems known to those skilled in the art.

For the purposes of the present invention, by polycarbonate-based resin it is meant:

a) a mixture containing at least 10% by weight of polyester of the bisphenol-A carbonic acid, where the remaining fraction of the mixture includes resins such as, for example, polystyrenes, polyesters, polyamides, polyisobutylenes, polybutenes, polyphenols, ABS;

b) a copolymer in which the repeating units are made up of at least 10% of the bisphenol-A carbonic acid ester.

This polycarbonate-based resin must have the following minimum mechanical characteristics:

- Elongation at break> 100%, measured according to ISO RS27

- Tensile modulus of elasticity> 1500 MPa, measured according to ISO R527

- No fracture on impact according to the Charpy test conducted on a specimen at a temperature of -30 ° C, according to the ISO 179-1 EU standard.

For example, in a preferred embodiment, in the case in which the polycarbonate-based resin is constituted by a copolymer (case b)) the remaining repetitive units thereof are represented by 1,1-bis (4-hydroxyphenyl) - 3,3,5-trimethylcyclohexane (BPTMC), while not excluding other constituents.

Purely by way of example, as further components of the polycarbonate-based copolymers, the following can be used: siloxane, succinic anhydride, diphenylcarbonate, poly (alkylene terephthalate).

The polycarbonate-based resin is dissolved in a special solvent chosen on the basis of the characteristics of the resin itself. Which solvents can be used for example: acetone, methyl-ethyl-ketone, ethyl acetate, perchlorethylene, water.

The solvent is present in quantities ranging from 10% to 900%.

Mineral fillers can be added to the solution thus obtained, such as boron carbide, silicon carbide, silicon oxide in the form of powders.

In addition, other polymeric substances may also be present in the solution, even previously solutes, such as fluorocarbon polymers or silicone polymers such as to confer water repellence, for example.

The polycarbonate-based resin solution is applied to the textile structure with known methods such as for example by padding, by spraying, by immersion, by doctor blade.

Typically, an amount of polycarbonate-based resin in the dry state comprised between 5 g / m <2> and 200 g / m <2> is applied, preferably between 50 g / m <2> and 100 g / m <2> . In a preferred embodiment, the viscosity of the polycarbonate-based resin solution is adjusted in such a way as to allow total impregnation of all the fibers of the yarns making up the structure itself.

Alternatively, if you want to give the textile structure greater flexibility, the viscosity of the solution is regulated (increased) so that it is unable to penetrate through all the fibers of the yarns, thus leaving some fibers not impregnated. The fraction of fibers not impregnated with the polycarbonate-based resin solution can be further impregnated with an additional resin of a different nature from that based on polycarbonate. For example, this further resin can be of the elastomeric, thermosetting or viscoelastic type, also in mixture.

Advantageously, this further resin has a tensile modulus of elasticity that is at least 10% lower than the tensile modulus of the polycarbonate-based resin.

Also in this case these polymers can be loaded with fillers.

This further resin can also be suitably dissolved in a solvent in such a quantity as to obtain a solution having a desired viscosity and be applied with known methods similar to those already indicated above.

Typically, this further resin is applied in quantities ranging from 5 g / m <2> to 100 g / m <2> in the dry state.

This further resin could also be applied in the form of a film, which can be laminated on one or both surfaces of the textile structure.

After each impregnation of the textile structure with the polycarbonate-based resin or with the additional resin, an elimination treatment of the solvent used for the solution used is performed, be it that of polycarbonate-based resin or that of the further one. resin. The elimination of the solvent can take place for example by evaporation in special ovens.

The textile structure thus treated, that is, after the elimination of the solvent, is subjected to calendering or pressing, preferably by continuous pressing, in order to reduce its thickness by at least 10% compared to the value corresponding to the weaving phase.

To this end, the impregnated textile structure is subjected to a pressure of at least 10 bar at a temperature of> 200 ° C, so as to reduce its thickness by at least 10% compared to the thickness during the weaving phase.

In a preferred embodiment, a pressure of at least 80 bar is applied at a temperature greater than 200 ° C for a few tens of seconds until a reduction in the thickness of the textile structure of at least 15% is obtained with a consequent increase in the flexibility of the fabric. 50%.

The application of such a high pressure also increases what, in the jargon of the sector, is called the â € œcovering factorâ € and favors the distribution and penetration of the polycarbonate-based resin or of the additional resin into the fibers. .

In figures 3 and 4 the fabric 1 is shown in section before and after pressing so as to highlight the variation in the shape of the cross-section of the threads, which passes from circular to substantially â € œflattenedâ € and a better coverage of the empty spaces by of the fibers of the threads.

This seamless structure is more difficult to penetrate by bullets and sharp and / or pointed elements.

It has surprisingly been found that the polycarbonate-based resin has a limited adhesion to the fibers of the ballistic threads used to make the textile structure object of the invention. The low adhesion value of the polycarbonate-based resin, contrary to what is normally believed, has proved surprisingly useful for the purposes of the present invention. In this way, in fact, the fibers of the ballistic threads, when hit by a bullet, can absorb and dissipate the energy deriving from the impact with this bullet by elastic elongation, working at the same time.

It has also been found that the polycarbonate-based resin applied in solution according to the present invention also gives the material impregnated with it an adequate resistance to the penetration of sharp and / or pointed elements.

The energy correlated with the penetration of cutting and / or pointed elements is generally of the order of 50 J, considerably lower than the energy correlated to the impact of a bullet which is generally greater than 1000 J. € ™ energy correlated with the penetration of sharp and / or pointed elements is not able to separate the fibers bonded together from the matrix, thus offering a monolithic surface difficult to penetrate by the sharp and / or pointed elements.

It was thus found that the application of a polycarbonate-based resin, rigid per se, to a textile structure made at least in part with ballistic threads, it is possible to obtain textile structures that simultaneously offer good resistance to € ™ impact of bullets and the penetration of sharp and / or pointed elements.

The substantial reduction in the thickness of the textile structure, in any case equal to at least 10% of the weaving thickness, gives it greater flexibility compared to known structures, since the rigidity is proportional to the thickness.

For example, in a textile structure with a thickness of 25-100 mm, a reduction in thickness of 15% involves, by a well-known mechanical law, an increase in flexibility of more than 50%.

Finally, the textile structure object of the present invention maintains the aforementioned characteristics of resistance and flexibility substantially unchanged in a wide temperature range between -30 ° C and 100 ° C, which allows them to be produced, stored and used in different environments and in various applications, even without resorting to conditioned environments and without a substantial variation in its resistance characteristics.

Moreover, the textile structures object of the present invention are advantageously odorless.

Textile structures object of the present invention can be used alone or in combination with other materials, such as for example foams, fabrics, non-woven fabrics, felts, polymeric films and more, to make articles, in particular personal protection articles, resistant to wear. ™ impact of bullets and the penetration of sharp and / or pointed elements.

Finally, the textile structure and the method object of the present invention are illustrated with reference to the following non-limiting examples.

EXAMPLE 1 (warp and weft fabric with polycarbonate resin in copolymer form)

A warp and weft fabric was woven with ballistic yarns having a count of 550 dtex.

The weight of this fabric is 155 g / m <2> with a thickness of 0.23 mm, with a weft and warp yarn density of 13.2.

A BPA BPTMC copolymer was used as the polycarbonate-based resin.

A solution of this resin was prepared using ethyl acetate as solvent, with a resin / solvent ratio of 25% / 75%.

The fabric was totally impregnated with this solution and subsequently subjected to a solvent elimination treatment by evaporation in stenter.

The quantity in the dry state of resin applied to the fabric is 45 g / m <2>.

The fabric thus obtained was subjected to a pressure of 80 bar, at a temperature of 220 ° C for a time of approximately 30 sec.

At the end of pressing, the fabric has a thickness of 0.19 mm.

This fabric has been subjected to impact resistance tests according to the HOSDB level HG2e KR2 standard using 34 layers.

It was thus found that the fabric passes (â € œpassesâ €) this test with respect to both knife penetration and bullet penetration:

Try it with a knife: â € œpassâ €

Proof with bullet: â € œpassâ €

EXAMPLE 2

A fabric like that of example 1 was used, impregnated on one side only at 70%.

The quantity of resin in the dry state applied to the fabric is 31 g / m2.

After pressing under the same conditions indicated above, the thickness is 0.18 mm.

This fabric was subjected to the same tests indicated in example 1, giving the same results, that is, passing them.

Try it with a knife: â € œpassâ €

Proof with bullet: â € œpassâ €

EXAMPLE 3 (warp / weft fabric with polycarbonate-based resin in the form of a mixture)

A warp and weft fabric was prepared as indicated in example 1, which, in a similar way to that indicated in example 1, was totally impregnated with a polycarbonate-based resin consisting of a mixture of 90% polycarbonate and 10% polybutene.

The quantity of resin applied in the dry state is equal to 45 g / m2.

Also in this case, the fabric was subjected to the same tests indicated in example 1, giving the same results, that is, passing them.

Try it with a knife: â € œpassâ €

Proof with bullet: â € œpassâ €

This fabric was also tested with a .357 S.P. Remington, overcoming it.

EXAMPLE 4 (comparative)

A warp and weft fabric was prepared with yarns of 440 dtex count, yarn density in the warp and weft equal to 12.2 per cm. This fabric has been impregnated with thermosetting phenolic resin.

This fabric is subjected to the same tests indicated in example 1 using 43 layers for a total weight of 6,800 kg / m <2>, passing, that is, overcoming those â € œknifeâ €, but not passing, that is not passing , the bullet ones.

Try it with a 50 J knife: â € œpassâ €

Try it with 33 J knife: â € œPassâ €

Test with 9MM bullet: â € œdoes not passâ €

Test with .357 Remington bullet: â € œdoes not passâ € EXAMPLE 5 (comparative)

A warp and weft fabric was prepared with 1100 dtex threads, weft and warp thread density equal to 8.6 threads / cm, with a total weight of 190 g / m <2>. This fabric has been laminated with two ionomeric resin films placed on the two opposite faces of it and weighing 90 g / m <2>. This fabric is subjected to the same tests indicated in example 1 using 24 layers for a total weight of 6,800 kg / m <2>, passing, that is, overcoming those â € œknifeâ €, but not passing, that is not passing , the bullet ones.

Try it with a knife: â € œpassâ €

Bullet test: â € œdoes not passâ €

Test with .357 Remington bullet: â € œdoes not passâ € EXAMPLE 6 (comparative)

Two warp and weft fabrics were prepared, each with xx dtex yarns, weft and warp yarn density equal to 7.4 yarns / cm, with a total weight of 140 g / m <2>. The two layers of fabric were glued together with the interposition of a PC film, obtaining a structure with a total weight of 360 g / m2.

This structure was subjected to the same tests indicated in example 1 using 19 layers for a total weight of 6,800 kg / m <2>, obtaining the following results

Try it with a knife: â € œpassâ €

Bullet test: â € œdoes not passâ €

Claims (12)

CLAIMS 1) Textile structure resistant to the impact of bullets and the penetration of sharp and / or pointed elements, made at least in part with ballistic threads, characterized by being at least partially impregnated with a polycarbonate-based resin, in the form of a copolymer or in a mixture with other polymers, dissolved in solvent, said structure having a thickness less than at least 10% than the thickness corresponding to the weaving phase thereof. 2) Textile structure according to claim 1, characterized in that said polycarbonate-based resin is a mixture containing at least 10% by weight of polyester of the bisphenol-A carbonic acid. 3) Textile structure according to claim 1, characterized by the fact that said resin is a copolymer in which the repetitive units are made up for at least 10% of Bisphenol-A carbonic acid ester. 4) Textile structure according to claim 3, characterized in that the remaining repetitive units of said copolymer are represented by 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (BPTMC). 5) Textile structure according to one or more of the preceding claims, characterized in that said resin has the following minimum characteristics: - Elongation at break> 100%, measured according to ISO RS27; - Tensile modulus of elasticity> 1500 MPa, measured according to ISO R527; - No impact fracture according to the Charpy standard conducted on a specimen at a temperature of -30 ° C, according to the ISO 179-1 EU standard. 6) Textile structure according to one or more of the preceding claims, characterized in that it has a thickness less than at least 10% of the thickness corresponding to the weaving phase thereof, following application of a pressure of at least 10 bar. 7) Textile structure according to one or more of the preceding claims, characterized in that it comprises a warp and weft fabric, which is made at least in part with ballistic yarns, or a warp and weft structure interlaced with at least two layers of yarns unidirectional, in which the threads of each layer are parallel to each other and the threads of the two layers are arranged with respect to each other at an angle between 0 ° and 90 ° and in which at least part of at least said unidirectional threads are ballistic threads. 8) Textile structure according to one or more of the preceding claims, characterized in that the fibers impregnated with said polycarbonate-based resin are equal to at least 10% of the total number of fibers. 9) Textile structure according to one or more of the preceding claims, characterized in that it comprises a quantity of said polycarbonate-based resin in the dry state comprised between 5g / m <2> and 200g / m <2>. 10) Textile structure according to one or more of the preceding claims, characterized in that the fiber fraction not impregnated with said polycarbonate-based resin is impregnated with a further elastomeric, plastomeric, thermosetting or viscoelastic resin, also in blend with each other. 11) Textile structure according to claim 10, characterized in that it comprises an amount of said further resin in the dry state comprised between 5 g / m <2> and 100 g / m <2>. 12) Textile structure according to one or more of the preceding claims, characterized by the fact that said ballistic yarns are continuous yarns also twisted, textured, taslanized, with a count between 25 dtex and 10000 dtex and having the following minimum mechanical characteristics: - Tensile strength> 7 g / dtex (according to ISO 627-1-2) - Tensile modulus of elasticity> 200 g / dtex (according to ISO R527) - Energy at break> 8 J / g (according to ASTMD 2256 standard) 13) Production method of a textile structure resistant to the impact of bullets and the penetration of sharp and / or pointed elements according to one or more of claims 1 to 12, comprising the phases consisting in: a) forming a textile structure made at least in part with ballistic threads; b) at least partially impregnating said textile structure with a polycarbonate-based resin, in the form of a copolymer or in a mixture with other polymers, dissolved in solvent; c) remove the solvent used for the solution from the impregnated textile structure, d) pressing the textile structure impregnated and deprived of the solvent until obtaining a thickness reduction of at least 10% of the thickness during the forming phase. 14) Method according to claim 13, further comprising, after said elimination step c) and before said pressing step d), a further step of impregnating said textile structure with a further resin. 15) Method according to claim 14, wherein said further resin is applied dissolved in solvent, a further elimination step being provided before said pressing step d) from the textile structure thus re-impregnated with the solvent used for the solution of said further resin. 16) Method according to one or more of claims 13 to 15, wherein said forming consists in weaving a warp and weft fabric, in which at least part of the weft and / or warp threads are ballistic threads, or in overlapping at least two layers of unidirectional threads, in which the threads of each layer are parallel to each other and the threads of the two layers are arranged with respect to each other at an angle between 0 ° and 90 °, interlacing the threads of said two layers with said structure weft and warp and in which at least part of at least at least said unidirectional yarns are ballistic yarns. 17) Method according to one or more of claims 13 to 16, wherein said polycarbonate-based resin is a mixture containing at least 10% by weight of polyester of the bisphenol-A carbonic acid or a copolymer in which the repeating units are made up of at least 10% of Bisphenol-A carbonic acid ester. 18) Method according to claim 19, wherein said polycarbonate-based resin is a copolymer in which the remaining repeating units are represented by 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (BPTMC) . 19) Method according to one or more of claims 13 to 18, wherein said polycarbonate-based resin has the following minimum characteristics: - Elongation at break> 100%, measured according to ISO RS27 - Tensile modulus of elasticity> 1500 MPa, measured according to ISO R527 - No impact fracture according to the Charpy test conducted on a specimen at a temperature of -30 ° C, according to the ISO 179-1 EU standard. 20) Method according to one or more of claims 13 to 19, wherein said pressing consists in applying a pressure of at least 10 bar at a temperature of at least 200 ° C to obtain a thickness reduction of the impregnated textile structures of at least 10% of the frame forming thickness. 21) Method according to one or more of claims 13 to 20, wherein said pressing consists in applying a pressure of at least 80 bar at a temperature of at least 200 ° C to obtain a thickness reduction equal to at least 15% of the frame forming thickness.